This large-scale randomized school-based effectiveness trial will study whether the Adolescent Depression Awareness Program (ADAP), a program that has shown in one group pre-post and nonrandomized controlled studies to increase depression literacy among adolescents, has an impact on treatment-seeking behaviors. Depression is prevalent, costly and a major cause of disability and death worldwide. The onset of depression often occurs early in life, during teen or young adult years as 21-28 percent of adolescents experience an episode of major depression by the age of 19 years. The onset of depression during adolescence is associated with increased risk for Major depression during adulthood, substance dependence, educational underachievement, unemployment, and early parenthood. These difficulties are also often evident in adolescents with subclinical levels of depression. Depression has substantial continuity into adulthood with impaired functioning in work, social, and family life. The most severe consequence of untreated depression is suicide. Despite the high proportion of adolescents affected and disability associated with depression, there have been few large-scale school-based randomized trials investigating the effectiveness of universal interventions targeting depression among adolescents; and the results from these studies have been mixed. ADAP, a school-based depression education program developed in 1999 by a team of psychiatrists and psychiatric nurses from the Johns Hopkins University School of Medicine, has been implemented in 85 schools throughout the United States with over 20,000 ninth grade students. ADAP is delivered by school-personnel (trained health education teachers) as part of the standard high school health education curriculum. A randomized trial of the ADAP's effectiveness has not yet been conducted. We propose to assess the effectiveness of ADAP in increasing depression literacy and treatment seeking among adolescents in 66 schools (n=15,000) in five regions of the United States using a randomized, universal school-based effectiveness trial. We will also identify possible mediators and moderators of intervention impact (e.g., access to community mental health services, teacher characteristics, school characteristics, stigma, and fidelity).